Heat-dissipating substrate

ABSTRACT

Disclosed herein is a heat-dissipating substrate in order to improve heat-dissipating characteristics. The heat-dissipating substrate, comprising: a copper layer having a predetermined thickness; anodized insulating layers formed on upper and lower surfaces of the copper layer; and aluminum (Al) layers formed between the copper layer and the anodized insulating layer. Therefore, a heat-dissipating function of the base made of the aluminum (Al) layer and the copper (Cu) layer is improved, thereby making it possible to provide a high-output metal substrate appropriate for high-integration/high capacity electronic components.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of Korean Patent Application No.10-2010-0108130, filed on Nov. 2, 2010, entitled “Heat-DissipatingSubstrate and Fabricating Method of The Same”, which is herebyincorporated by reference in its entirety into this application.

BACKGROUND OF THE INVENTION

1. Technical Field

The present invention relates to a heat-dissipating substrate.

2. Description of the Related Art

Generally, with the development of a high-degree technology industrysuch as vehicles, a demand for high-integration/high-capacity electroniccomponents used therefor has also correspondingly increased.

In fabricating the high-integration/high-capacity electronic component,heat-dissipation has been importantly considered. That is, each of thehigh-integration/high-capacity electronic components on the substrategenerates high heat, which causes a function of each of the electroniccomponents to be deteriorated.

Accordingly, a demand for development of a substrate with highdissipating characteristics capable of rapidly and smoothly dissipatingheat generated from each of the high-integration/high-capacityelectronic components to the outside has increased.

Since an organic printed circuit board (PCB) or a metal substrateaccording to the prior art has low dissipating characteristics, it has arestriction in being used as a high-output substrate. An anodizedaluminum substrate has improved dissipating characteristics as comparedto the organic PCB and the metal substrate; however, has a restrictionin being used as the high-output substrate due to a limitation inthermal conductivity of aluminum.

For example, the anodized aluminum substrate 10 is formed by forming ananodized insulating layer 12 on a surface of an aluminum disc 11 throughan anodizing process, forming a metal layer 13 thereon through a drysputtering process or a wet electroless/electro plating process andforming a pattern on the metal layer 13 through a dry/wet etchingprocess or a lift-off process, as shown in FIG. 1. It is difficult touse the anodized aluminum substrate as the high-output substrate due tothe limitation in thermal conductivity of aluminum (for example, 5052aluminum alloy; ˜140 W/m·K).

SUMMARY OF THE INVENTION

The present invention has been made in an effort to provide aheat-dissipating substrate capable of improving the heat-dissipatingfunction by using a multi-layer structure made of a copper (Cu) layerand an aluminum (Al) layer.

Further, the present invention has been made in an effort to provide aheat-dissipating substrate capable of improving heat-dissipatingcharacteristics and minimizing weight increase by adjusting thethickness ratio of a copper (Cu) layer and an aluminum (Al) layer.

According to a first preferred embodiment of the present invention,there is provided A heat-dissipating substrate, comprising: a copperlayer having a predetermined thickness; and anodized insulating layersformed on upper and lower surfaces of the copper layer.

The heat-dissipating substrate may further include aluminum (Al) layersformed between the copper layer and the anodized insulating layer.

Further, The heat-dissipating substrate may further include a seed layerformed on the part of anodized insulating layer; and a metal layerformed on the seed layer.

The anodized insulating layer is formed on the surface of the aluminumlayer through an anodizing process.

The aluminum layers are formed at a thickness of 0.02 mm˜0.2 mm.

The copper layer and the aluminum layers are formed at a thickness ratioof 2:2 to 3:1.

The seed layer is performed by electroless plating or sputteringdeposition.

The metal layer is performed by wet plating or dry sputteringdeposition.

The seed layer is formed on the entire surface of anodized insulatinglayer, the metal layer is formed on the seed layer, and a part of theseed layer and the metal layer is removed by wet chemical etching,electrolytic etching or lift-off.

According to a Second preferred embodiment of the present invention,there is provided A heat-dissipating substrate, comprising: a copperlayer having a first area and second area of the upper surface or lowersurface, and a predetermined thickness; aluminum layers formed on firstarea of the upper surface or the lower surface; and anodized insulatingslayer formed on second area of the upper surface or the lower surface ofthe copper layer.

Further, The heat-dissipating substrate may further include a seed layerformed on the part of anodized insulating layer; and a metal layerformed on the seed layer.

The anodized insulating layer is formed on the surface of the aluminumlayer through an anodizing process.

The aluminum layers are formed at a thickness of 0.02 mm˜0.2 mm.

The copper layer and the aluminum layers are formed at a thickness ratioof 2:2 to 3:1.

The seed layer step is performed by electroless plating or sputteringdeposition.

The metal layer is performed by wet plating or dry sputteringdeposition.

The seed layer is formed on the entire surface of anodized insulatinglayer, the metal layer is formed on the seed layer, and a part of theseed layer and the metal layer is removed by wet chemical etching,electrolytic etching or lift-off.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross sectional view showing an anodized aluminum substrateaccording to the prior art;

FIG. 2 is a cross-sectional view showing a first embodiment of ananodized multi-layer metal substrate to which the present invention isapplied;

FIGS. 3A to 3E are process views showing a first embodiment of afabricating method of an anodized multi-layer metal substrate to whichthe present invention is applied;

FIGS. 4A to 4E are process views showing a second embodiment of afabricating method of an anodized multi-layer metal substrate to whichthe present invention is applied;

FIGS. 5A to 5E are process views showing a third embodiment of afabricating method of an anodized multi-layer metal substrate to whichthe present invention is applied;

FIG. 6 is a cross-sectional view showing a third embodiment of ananodized multi-layer metal substrate to which the present invention isapplied;

FIG. 7 is a graph showing thermal conductivity depending on the changein the thickness of a copper layer in an anodized multi-layer metalsubstrate to which the present invention is applied; and

FIG. 8 is a graph showing thermal conductivity depending on the changein the thickness of a copper layer in an anodized multi-layer metalsubstrate to which the present invention is applied.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Various features and advantages of the present invention will be moreobvious from the following description with reference to theaccompanying drawings.

The terms and words used in the present specification and claims shouldnot be interpreted as being limited to typical meanings or dictionarydefinitions, but should be interpreted as having meanings and conceptsrelevant to the technical scope of the present invention based on therule according to which an inventor can appropriately define the conceptof the term to describe most appropriately the best method he or sheknows for carrying out the invention.

The above and other objects, features and advantages of the presentinvention will be more clearly understood from the following detaileddescription taken in conjunction with the accompanying drawings. In thespecification, in adding reference numerals to components throughout thedrawings, it is to be noted that like reference numerals designate likecomponents even though components are shown in different drawings.Further, when it is determined that the detailed description of theknown art related to the present invention may obscure the gist of thepresent invention, the detailed description thereof will be omitted.

Preferred embodiments of the present invention will be described indetail with reference to the accompanying drawings.

A fabricating method of a heat-dissipating substrate according to apreferred embodiment of the present invention includes (A) formingaluminum (Al) layers (120) on upper and lower surfaces of a copper (Cu)layer 110 and (B) forming anodized insulating layers 130 on surfaces ofupper and lower aluminum layers, as shown in FIGS. 2 to 8.

Accordingly, an anodized multi-layer metal substrate 100, which is aheat-dissipating substrate according to the preferred embodiment of thepresent invention, forms the copper layer 110 having thermalconductivity of ±350 W/m·K between the upper and lower aluminum layers120 having thermal conductivity of ±140 W/m·K to have total thermalconductivity 140 to 350 W/m·K. At this time, thermal conductivity andweight of the anodized multi-layer metal substrate 100 may be adjustedaccording to the thicknesses of the copper layer 110 and the aluminumlayers 120.

At step (A), for example, in the state in which the aluminum layers 120in a plate form are closely attached on and beneath the copper layer110, the aluminum layers may be bonded onto the copper layer by rolling.

The aluminum layers 120 are formed on the upper and lower surfaces ofthe copper layer 110 in order to form the anodized insulating layers 130by an anodizing process. In order to form the anodized insulating layer130, the aluminum layer should be formed at a thickness of at least 0.02mm or more.

The thickness ratio of the copper layer 110 and the aluminum layers 120may be adjusted to have thermal conductivity in the range of 140 to 350W/m·K. For example, as shown in FIG. 7, in the case in which the totalthickness of the copper layer 110 and the aluminum layers 120 except theanodized insulating layer 130 is 4 mm, when the thickness of the copperlayer 110 is 2 mm, thermal conductivity of the anodized multi-layermetal substrate 100 is 200 W/m·K, and when the thickness thereof is 3mm, thermal conductivity thereof is 255 W/m·K.

The thickness ratio of the copper layer 110 and the aluminum layers 120may be adjusted to have the weight of the anodized multi-layer metalsubstrate 100 in the range of 11 to 35 kg/m². For example, as shown inFIG. 8, in the case in which the total thickness of the copper layer 110and the aluminum layers 120 except the anodized insulating layer 130 is4 mm, when the thickness of the copper layer 110 is 2 mm, the weight ofthe anodized multi-layer metal substrate 100 is 23.5 kg/m², and when thethickness thereof is 3 mm, the weight thereof is 29.5 kg/m².

Accordingly, as shown in FIGS. 7 and 8, the copper layer 110 and thealuminum layers 120 are formed at a thickness ratio of 2:2 to 3:1 tomaintain optimal thermal conductivity and weight.

At step (B), for example, the anodized insulating layers 130 are formedon the surfaces of the upper and lower aluminum layers 120 through theanodizing process. At this time, as an example, it is possible to allowthe entire or partial thickness of the aluminum layers 120 to become theanodized insulating layers 130 and allow the entire or partial surfaceof the aluminum layers 120 to become the anodized insulating layers 130,through the anodizing process.

That is, the anodized insulating layers 130 are formed by oxidizing thealuminum layers 120 through the anodizing process. In a firstembodiment, a predetermined thickness with respect to the entire surfaceof the aluminum layers 120 becomes the anodized insulating layers 130,as shown in FIGS. 2 and 3A to 3E. In a second embodiment, the entirethickness with respect to the entire surface of the aluminum layers 120becomes the anodized insulating layers 130, as shown in FIGS. 4A to 4E.In a third embodiment, the entire thickness with respect to the partialsurface of the aluminum layers 120 becomes the anodized insulatinglayers 130, as shown in FIGS. 5A to 5E and 6.

Meanwhile, although not included in the embodiments, the partialthickness with respect to the partial surface of the aluminum layers 120may become the anodized insulating layers 130. It may be predicted byclaim 3 and claim 4 of the present invention that the aluminum layers120 may be formed both on and beneath the copper layer 110.

While heat-dissipation may be performed in a horizontal direction alongthe copper layer 110 in the first and second embodiments,heat-dissipation may be performed in a vertical direction along thealuminum layers while being performed in the horizontal direction in thethird embodiment.

Meanwhile, the fabricating method of the heat-dissipating substrateaccording to the preferred embodiment of the present invention furtherincludes (C) forming a seed layer 140 on the anodized insulating layer130, (D) forming a metal layer 150 on the seed layer 140 and (E)partially removing the seed layer 140 and the metal layer 150 to form apattern.

At step (C), the seed layer 140 may be formed by electroless plating orsputtering deposition, for example. That is, the electroless plating orthe sputtering deposition is used in order to form the seed layer 140 onthe anodized insulating layer 130 that does not pass electricity.

At step (D), the metal layer 150 is formed by wet plating or drysputtering deposition.

At step (E), the seed layer 140 and the metal layer 150 are partiallyremoved by wet chemical etching, electrolytic etching or lift-off toform the pattern.

Each of the embodiments of a fabricating method of a heat-dissipatingsubstrate and a heat-dissipating substrate fabricated using thefabricating method according to a preferred embodiment of the presentinvention will be described in detail below.

In the first embodiment, the aluminum layers 120 are bonded onto theupper and lower surfaces of the copper layer 110 at a thickness of atleast 0.02 mm or more by rolling, as shown in FIG. 3A. Then, in thestate of connecting the aluminum layers 120 to electrodes, anelectrolyte is injected therein to form the anodized insulating layers130 on the surfaces of the aluminum layers 120.

In this case, the anodized insulating layers 130 are uniformly formedover the entire surfaces of the aluminum layers 120 as shown in FIG. 3B.The amount of time of the anodizing process is adjusted, such that thealuminum layers 120 having a predetermined thickness remain on the upperand lower surfaces of the copper layer 110.

Thereafter, the seed layer 140 is formed on the anodized insulatinglayer 130 as shown in FIG. 3C, the metal layer 150 is formed on the seedlayer as shown in FIG. 3D, and the seed layer 140 and the metal layer150 are partially removed to form the pattern as shown in FIG. 3E.

According to the fabricating method of the present invention asdescribed above, the anodized multi-layer metal substrate 100, which isthe heat-dissipating substrate, including a configuration made of thecopper (Cu) layer 110 having a predetermined thickness, the aluminum(Al) layers 120 formed on and beneath the copper layer 110 and theanodized insulating layers 130 formed on the surfaces of the upper andlower the aluminum layers 120, as shown in FIG. 2, is provided. At thistime, the pattern made of the seed layer 140 formed on the anodizedinsulating layer 130 and the metal layer 150 formed on the seed layer140 is formed.

In the second embodiment, the aluminum layers 120 are bonded onto theupper and lower surfaces of the copper layer 110 at a thickness of atleast 0.02 mm or more by rolling, as shown in FIG. 4A. Then, in thestate of connecting the aluminum layers 120 to electrodes, anelectrolyte is injected therein to form the anodized insulating layers130 on the surfaces of the aluminum layer 120.

In this case, the anodized insulating layers 130 are uniformly formedover the entire surface of the aluminum layers 120 as shown in FIG. 4B.The amount of time of the anodizing process is adjusted, such that theentirety of the aluminum layers 120 formed on the surfaces of the copperlayer 110 is oxidized.

Thereafter, the seed layer 140 is formed on the anodized insulatinglayer 130 as shown in FIG. 4C, the metal layer 150 is formed on the seedlayer as shown in FIG. 4D, and the seed layer 140 and the metal layer150 are partially removed to form a pattern as shown in FIG. 4E.

According to the fabricating method of the present invention asdescribed above, the anodized multi-layer metal substrate 100 includinga configuration made of the copper (Cu) layer 110 having a predeterminedthickness and the anodized insulating layers 130 formed on the upper andlower surfaces of the copper layer 110, as shown in FIG. 4E, isprovided. At this time, the pattern made of the seed layer 140 formed onthe anodized insulating layer 130 and the metal layer 150 formed on theseed layer 140 is formed.

In the third embodiment, the aluminum layers 120 are bonded onto theupper and lower surfaces of the copper layer 110 at a thickness of atleast 0.02 mm or more by rolling, as shown in FIG. 5A. Then, in thestate of connecting the aluminum layers 120 to electrodes, anelectrolyte is injected therein to form the anodized insulating layers130 on the surfaces of the aluminum layers 120.

At this time, the anodizing is partially performed on the entire surfaceof the aluminum layer 120, such that the copper layer having a firstarea and second area of the upper surface or lower surface, and aluminumlayers formed on first area of the upper surface or the lower surface,and anodized insulatings layer formed on second area of the uppersurface or the lower surface of the copper layer. In order toselectively perform anodizing, for example, a tape may be adhered or achemical may be coated so as to prevent oxidation on the surface of thealuminum layer 120. The portion in the aluminum layer 120 subjected toanodizing to become the anodized insulating layer 130 corresponds to anarea in which the pattern is subsequently formed. The anodizedinsulating layer 130 should be formed to be wider than the area in whichthe pattern is formed, in order to perform an electrical insulation.

Thereafter, the seed layer 140 is formed on the aluminum layer 120 andthe anodized insulating layer 130 as shown in FIG. 5C, the metal layer150 is formed on the seed layer 140 as shown in FIG. 5D, and the seedlayer 140 and the metal layer 150 are partially removed to form apattern as shown in FIG. 5E.

According to the fabricating method of the preferred embodiments of thepresent invention as described above, the anodized multi-layer metalsubstrate 100 including a configuration made of the copper (Cu) layer110 having a predetermined thickness, an aluminum layer 120 formed onthe upper or the lower surface of the copper layer 110 and selectivelyformed in a predetermined area and the anodized insulating layer 130formed on the upper surface or the lower surface of the copper layer 110and formed in an area except the aluminum layers 120, as shown in FIG.6, is provided. At this time, the pattern made of the seed layer 140formed on the anodized insulating layer 130 and the metal layer 150formed on the seed layer 140 is formed.

According to the heat-dissipating substrate and the fabricating methodof the same of the preferred embodiments of the present invention, theheat-dissipating function is improved through a multi-layer structuremade of the copper (Cu) layer and the aluminum (Al) layer, therebymaking it possible to provide the high-output metal substrateappropriate for the high-integration/high capacity electroniccomponents.

According to the heat-dissipating substrate and the fabricating methodof the same of the preferred embodiments of the present invention, thethickness ratio of the copper (Cu) layer and the aluminum (al) layer isadjusted to improve the heat-dissipating characteristics as well asminimize the weight increase due to the copper, thereby allowing theheat-dissipating substrate to be used as an electrical high-outputsubstrate that needs to have light weight.

Although the preferred embodiments of the present invention have beendisclosed for illustrative purposes, they are for specificallyexplaining the present invention. Thus a heat-dissipating substrate anda fabricating method of the same according to the present invention arenot limited thereto, but those skilled in the art will appreciate thatvarious modifications and alterations are possible, without departingfrom the scope and spirit of the invention.

Accordingly, such modifications and alterations should also beunderstood to fall within the scope of the present invention. A specificprotective scope of the present invention can be defined by theaccompanying claims.

1. A heat-dissipating substrate, comprising: a copper layer having a predetermined thickness; and anodized insulating layers formed on upper and lower surfaces of the copper layer.
 2. The heat-dissipating substrate as set forth in claim 1, further comprising aluminum (Al) layers formed between the copper layer and the anodized insulating layer.
 3. The heat-dissipating substrate as set forth in claim 2, further comprising: a seed layer formed on the part of anodized insulating layer; and a metal layer formed on the seed layer.
 4. The heat-dissipating substrate as set forth in claim 2, wherein the anodized insulating layer is formed on the surface of the aluminum layer through an anodizing process.
 5. The heat-dissipating substrate as set forth in any one of claim 2, wherein the aluminum layers are formed at a thickness of 0.02 mm˜0.2 mm.
 6. The heat-dissipating substrate as set forth in claim 2, wherein the copper layer and the aluminum layers are formed at a thickness ratio of 2:2 to 3:1.
 7. The heat-dissipating substrate as set forth in claim 4, wherein the seed layer is performed by electroless plating or sputtering deposition.
 8. The heat-dissipating substrate as set forth in claim 4, wherein the metal layer is performed by wet plating or dry sputtering deposition.
 9. The heat-dissipating substrate as set forth in claim 4, wherein the seed layer is formed on the entire surface of anodized insulating layer, the metal layer is formed on the seed layer, and a part of the seed layer and the metal layer is removed by wet chemical etching, electrolytic etching or lift-off.
 10. A heat-dissipating substrate, comprising: a copper layer having a first area and second area of the upper surface or lower surface, and a predetermined thickness; aluminum layers formed on first area of the upper surface or the lower surface; and anodized insulatings layer formed on second area of the upper surface or the lower surface of the copper layer.
 11. The heat-dissipating substrate as set forth in claim 10, further comprising: a seed layer formed on the part of anodized insulating layer; and a metal layer formed on the seed layer.
 12. The heat-dissipating substrate as set forth in claim 10, wherein the anodized insulating layer is formed on the surface of the aluminum layer through an anodizing process.
 13. The heat-dissipating substrate as set forth in claim 10, wherein the aluminum layers are formed at a thickness of 0.02 mm˜0.2 mm.
 14. The heat-dissipating substrate as set forth in claim 10, wherein the copper layer and the aluminum layers are formed at a thickness ratio of 2:2 to 3:1.
 15. The heat-dissipating substrate as set forth in claim 11, wherein the seed layer step is performed by electroless plating or sputtering deposition.
 16. The heat-dissipating substrate as set forth in a claim 11, wherein the metal layer is performed by wet plating or dry sputtering deposition.
 17. The heat-dissipating substrate as set forth in claim 11, wherein the seed layer is formed on the entire surface of anodized insulating layer, the metal layer is formed on the seed layer, and a part of the seed layer and the metal layer is removed by wet chemical etching, electrolytic etching or lift-off. 